For example, there is known a vehicle headlamp where a lamp unit including a light source or the like is disposed inside a lamp outer casing that is configured by a cover and a lamp housing.
In such a lamp unit, a light quantity control mechanism for controlling the amount of light emitted from the light source is provided. The light quantity control mechanism includes a movable shade for changing the shielded amount of light emitted from the light source and a solenoid for actuating the movable shade (e.g., see FIG. 4 in Patent Document 1).
In the vehicle headlamp disclosed in Patent Document 1, an output shaft of the solenoid disposed on the front side and the movable shade disposed on the rear of the solenoid are connected to each other by a wire-like arm (link member). One end of the arm is rotatably connected to the output shaft and the other end (bent portion) thereof is slidably abutted against an engaging portion of the movable shade.
When the output shaft of the solenoid is moved in a left-right direction, the arm is rotated and the bent portion of the arm slides on the engaging portion of the movable shade. In this way, the movable shade is pivoted about a pivot shaft extending laterally.
As the movable shade is pivoted to a first position, the vehicle headlamp is switched to a low beam mode where a short distance ahead of a vehicle is irradiated. As the movable shade is pivoted to a second position, the vehicle headlamp is switched to a high beam mode where a long distance ahead of the vehicle is irradiated.